Originally reported as: https://github.com/mozilla/geckodriver/issues/1413 Since my Serde changes on bug 1396821 we no longer only screenshot the element but the viewport.

Now that we have better screenshot helpers for wdspec tests, which should get at least one more test added.

Here trace logs from before and after the Serde conversion: Before: > 1541067402261 webdriver::server DEBUG -> POST /session/767b55bb-aba8-2b4a-98fe-2f36b271ccca/element {"using": "css selector", "value": "[id=\"nothing2\"]"} > 1541067402263 Marionette TRACE 0 -> [0,3,"WebDriver:FindElement",{"using":"css selector","value":"[id=\"nothing2\"]"}] > 1541067402280 Marionette TRACE 0 <- [1,3,null,{"value":{"element-6066-11e4-a52e-4f735466cecf":"12b11b17-af5a-974b-87d4-8d5d4b563c74","ELEMENT":"12b11b17-af5a-974b-87d4-8d5d4b563c74"}}] > 1541067402281 webdriver::server DEBUG <- 200 OK {"value":{"element-6066-11e4-a52e-4f735466cecf":"12b11b17-af5a-974b-87d4-8d5d4b563c74"}} > 1541067402282 webdriver::server DEBUG -> GET /session/767b55bb-aba8-2b4a-98fe-2f36b271ccca/element/12b11b17-af5a-974b-87d4-8d5d4b563c74/screenshot > 1541067402284 Marionette TRACE 0 -> [0,4,"WebDriver:TakeScreenshot",{"full":false,"highlights":[],"id":"12b11b17-af5a-974b-87d4-8d5d4b563c74"}] After: > 1541070433340 webdriver::server DEBUG -> POST /session/0c2895f5-8f84-934f-980e-43b7a3540654/element {"using": "css selector", "value": "[id=\"nothing2\"]"} > 1541070433349 Marionette TRACE 0 -> [0,3,"WebDriver:FindElement",{"using":"css selector","value":"[id=\"nothing2\"]"}] > 1541070433355 Marionette TRACE 0 <- [1,3,null,{"value":{"element-6066-11e4-a52e-4f735466cecf":"20519704-b136-1e4e-a4a2-e69b4296451e"}}] > 1541070433357 webdriver::server DEBUG <- 200 OK {"value":{"element-6066-11e4-a52e-4f735466cecf":"20519704-b136-1e4e-a4a2-e69b4296451e"}} > 1541070433358 webdriver::server DEBUG -> GET /session/0c2895f5-8f84-934f-980e-43b7a3540654/element/20519704-b136-1e4e-a4a2-e69b4296451e/screenshot > 1541070433361 Marionette TRACE 0 -> [0,4,"WebDriver:TakeScreenshot",{"element":{"element-6066-11e4-a52e-4f735466cecf":"20519704-b136-1e4e-a4a2-e69b4296451e"},"full":false,"highlights":[]}] So the problem is that we now pass the element via `element` but not `id`. As such it is not recognized.

Ouch: https://dxr.mozilla.org/mozilla-central/rev/c291143e24019097d087f9307e59b49facaf90cb/testing/geckodriver/src/marionette.rs#921-922 > data.insert("element".to_string(), serde_json::to_value(e)?); > // data.insert("id".to_string(), e.id.to_json()); Looks like that I missed to uncomment this line when finalizing the patch. :/ Further we can also remove the implementation of `to_marionette()` for `TakeScreenshotParameters` because it's not used anywhere.

First try job including Rust tests, where Wd1 failed for all platforms because I didn't check our Mozilla specific wdspec tests: https://treeherder.mozilla.org/#/jobs?repo=try&revision=d5935ee5dbdf4c329432edb96891f24679ed8c5c&selectedJob=209168101 Most recent try job with lesser changes to helpers, which will fix the Wd1 failures: https://treeherder.mozilla.org/#/jobs?repo=try&revision=d285c58039686686d529e11992e7edadc9d4ec52

Depends on D10626

Depends on D10627

Pushed by hskupin@mozilla.com: https://hg.mozilla.org/integration/autoland/rev/fb03520d8991 [geckodriver] Fix serialization of "Take Element Screenshot" parameters for Marionette. r=ato https://hg.mozilla.org/integration/autoland/rev/8ee95012eaf0 [wdspec] Use shared assert_png() method in screenshot tests. r=ato https://hg.mozilla.org/integration/autoland/rev/076d32d1343f [wdspec] Assert for expected screenshot dimensions. r=ato

Created web-platform-tests PR https://github.com/web-platform-tests/wpt/pull/13929 for changes under testing/web-platform/tests

Can't merge web-platform-tests PR due to failing upstream checks: Github PR https://github.com/web-platform-tests/wpt/pull/13929 * continuous-integration/travis-ci/pr (https://travis-ci.org/web-platform-tests/wpt/builds/451005144?utm_source=github_status&utm_medium=notification) * Taskcluster (pull_request) (https://tools.taskcluster.net/task-group-inspector/#/LIrnFNp0T-qTtN05hRn8Ow)

https://hg.mozilla.org/mozilla-central/rev/fb03520d8991 https://hg.mozilla.org/mozilla-central/rev/8ee95012eaf0 https://hg.mozilla.org/mozilla-central/rev/076d32d1343f

https://github.com/web-platform-tests/wpt/pull/13929 got merged about 30min ago. Did the sync bot got stuck somewhere so it didn't notice that?

Upstream PR merged

I poked it a bit.